Getting a drivers license has been as much a rite of passage as the high school prom, but a new study suggests that young Americans are no longer rushing to get a driver’s license the moment they are eligible – and the Internet may be a major reason for that delay.

Even in their 30s, Americans are less likely to be licensed to drive, according to a report by the University of Michigan’s Transportation Research Institute, or UMTRI. But the trend did not show up among older drivers who are less likely to rely on online communications for their social interactions.

“It is possible that the availability of virtual contact through electronic means reduces the need for actual contact among young people,” said UMTRI lead researcher Michael Sivak. “Furthermore, some young people feel that driving interferes with texting and other electronic communication.”

The decline can be measured in a number of ways. According to UMTRI, a third of all licensed drivers in U.S. were under 30 back in 1983. Today, that’s down to 22%, despite the huge number of so-called Millennials, a generation rivaling the Baby Boom in size. And while those under 40 accounted for over half of all drivers in 1983, the figure is now down to less than 40%.

In particular, UMTRI and other organizations are finding that American teens are simply delaying the big step of getting a license. Where 69% of 17-year-olds were licensed back in 1983, that was down to 50% in 2008.

The fact that teens are more likely to rely on high-tech social interaction is clearly considered a factor in the delay. But there are others, including the weak economy, high unemployment among the young, a growing migration of young people to urban centers where cars are less necessary, and the high cost of owning a vehicle.

The U.S. isn’t the only country where the trend has been measured. Another study found similar declines in seven of 14 countries, including Germany, South Korea, Canada, Norway, Sweden and Great Britain, In Japan, the shift has been well documented for more than a decade and accompanies other shifting patterns among younger citizens – who also appear to be less willing to work the extended hours typical in that country since the end of the Second World War.

The older the age group, the less dramatic the decline, according to the UMTRI study, though the percentage of those holding a driver’s license fell 3.2% among 35 to 39-year-olds, it found.

The Michigan-based organization’s data was echoed in another study by the environmental organization, The Frontier Group, and the U.S. PIRG Education Fund, a consumer group.

They also report that, based on federal data, the number of miles driven by younger Americans has been on a sharp decline. Those between 16 and 34 years of age clocked an average 10,300 miles annually as recently as 2001. By 2009, that had dipped to just 7,900 miles a year.

The decline in young drivers hasn’t been ignored by the auto industry. In Japan, it’s a significant factor in the slow revival of that country’s automotive market since the bubble years of the 1980s and early 1990s.

U.S. makers also are worried about the potential impact on demand if more teens fail to get their licenses. “There’s a pretty significant shift in how people are viewing automobiles and transportation, in general,” said John McFarland, Chevy’s senior manager of global marketing.

General Motors’ largest division is displaying a pair of “affordable” concept vehicles at the New York Auto Show this month that it hopes will entice Millennial buyers into its showrooms – and perhaps encourage those without licenses to head to the local motor vehicle office.

The maker says it’s likely to produce a version of the Code 130R or Tru 140S – or something quite similar – in the next few years.

If it does, another bit of research by consulting firm Deloitte suggested Chevy should strongly consider using a “green” powertrain. A study released earlier this year found six of 10 Millennials would like to buy a hybrid or electric vehicles rather than a conventionally powered car, truck or crossover.

“Gen Y is familiar and comfortable with hybrid technology,” said Craig Giffi, Deloitte’s vice chairman and head of its auto practice, suggesting that the Millennials will “lead us away from traditional, gasoline-powered vehicles.”

A lower proportion of young people have a driver’s license today compared to their counterparts in the early 1980s–a trend not found among older age groups, an UMTRI study shows.

In 1983, a third of all licensed drivers in the United States were under age 30. Today, only about 22 percent of drivers are twentysomethings or teenagers. Further, more than half of all drivers in 1983 were under age 40, but today that number has fallen to less than 40 percent.

“It is possible that the availability of virtual contact through electronic means reduces the need for actual contact among young people,” said UMTRI research professor Michael Sivak. “Furthermore, some young people feel that driving interferes with texting and other electronic communication.”

In a new study in the journal Traffic Injury Prevention, Sivak and UMTRI colleague Brandon Schoettle examined the changes in the United States from 1983 to 2008 in the percentage of persons with driver’s licenses as a function of age.

They found that young people not only account for a lower percentage of today’s total licensed drivers, but that young drivers comprise a smaller portion of their age group as a whole, compared to 1983.

About 87 percent of 19-year-olds in 1983 had their licenses, but 25 years later, that percentage had dropped to about 75 percent. Other teen driving groups have also declined: 18-year-olds fell from 80 percent in 1983 to 65 percent in 2008, 17-year-olds decreased from 69 percent to 50 percent, and 16-year-olds slipped from 46 percent to 31 percent.

Drivers in their 20s and 30s also saw their ranks fall as a percentage of their age group population–down nearly 10 percentage points for twentysomethings and down about five percentage points for the thirtysomethings.